Baseline characteristics of propensity score-matched pneumonitis cohort
| Characteristic | Unmatched | Matched | ||
| ICI-treated controls without CIP | ICI-treated cases with CIP | ICI-treated controls without CIP | ICI-treated cases with CIP | |
| N | 19,504 | 254 | 254 | 254 |
| Demographics | ||||
| Age at index*—mean (SD) | 66.9 (10.2) | 68.2 (9.7) | 69.1 (9.7) | 68.2 (9.7) |
| Male sex*—no. (%) | 10,400 (53.3) | 157 (61.8) | 173 (68.1) | 157 (61.8) |
| Race/ethnicity*—no. (%) | ||||
| White | 14,570 (74.7) | 183 (72.0) | 187 (73.6) | 183 (72.0) |
| Black/African American | 2506 (12.8) | 23 (9.1) | 32 (12.6) | 23 (9.1) |
| Asian | 368 (1.9) | ≤10 (3.9) | ≤10 (3.9) | ≤10 (3.9) |
| American Indian/Native American | 60 (0.3) | 0 (0) | 0 (0) | 0 (0) |
| Native Hawaiian/Pacific Islander | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Unknown | 1990 (10.2) | 43 (16.9) | 30 (11.8) | 43 (16.9) |
| Cancer | ||||
| Secondary malignancy*—no. (%) | ||||
| Lymph nodes | 5202 (26.7) | 104 (40.9) | 107 (42.1) | 104 (40.9) |
| Respiratory/digestive | 5855 (30.0) | 106 (41.7) | 100 (3.4) | 106 (41.7) |
| Other | 9198 (47.2) | 116 (45.7) | 115 (45.3) | 116 (45.7) |
| Neuroendocrine tumor | 241 (1.2) | ≤10 (3.9) | ≤10 (3.9) | ≤10 (3.9) |
| Type of ICI* | ||||
| PD-1 | 14,901 (76.4) | 186 (73.2) | 193 (76.0) | 186 (73.2) |
| PD-L1 | 4751 (24.4) | 71 (28.0) | 63 (24.8) | 70 (27.6) |
| ICI line of therapy*—no. (%) | ||||
| First line | 6648 (34.1) | 96 (37.7) | 117 (46.1) | 96 (37.7) |
| Second line | 5396 (27.7) | 70 (27.6) | 70 (27.6) | 70 (27.6) |
| Third and above | 2105 (10.8) | 23 (9.1) | 13 (5.1) | 23 (9.1) |
| Coexisting conditions | ||||
| Personal history of nicotine dependence* | 6737 (34.5) | 128 (50.4) | 140 (55.1) | 128 (50.4) |
| Prior encounter for antineoplastic radiation therapy* | 2109 (10.8) | 48 (18.9) | 48 (18.9) | 48 (18.9) |
| History of acute radiation pneumonitis* | 169 (0.9) | ≤10 (3.9) | ≤10 (3.9) | ≤10 (3.9) |
| History of prior lung disease | ||||
| Chronic obstructive pulmonary disease* | 5565 (28.5) | 100 (39.4) | 85 (33.5) | 100 (39.4) |
| Asthma* | 922 (4.7) | 17 (6.7) | ≤10 (3.9) | 17 (6.7) |
| Pleural disease* | 4470 (22.9) | 91 (35.8) | 84 (33.1) | 91 (35.8) |
Demographic data were obtained from coded TriNetX data. Type of ICI counts patients who received both a PD-1 or PD-L1 inhibitor at any point in both categories. Line of therapy data were not available for every patient.
*Starred variables were used for propensity score matching.
CIP, checkpoint-inhibitor pneumonitis ; ICI, immune checkpoint inhibitors ; PD-1, programmed cell death receptor 1 ; PD-L1, programmed cell death ligand 1 .